Coupon code change automatically prize

First i made new coupon codes in admin panel. If customers ordering atleast 50 euros stuffs, he get 5% preference, if 100 euros he get 10%, but only with cash not with credit cards. But i want if customer ordering atleast 50 or 100 euros stuffs, coupon change automatically prizes. I dont want see that in checkout. And i use Ajax Quick Checkout module.
Sorry my english isnt so good, so i hope you understand my problem. Website adress is www.koosost.ee

Since your enquiry is about an installed extension that you wish to customize, I would suggest to contact the developer of that extension or to post a request in the Commercial Support section of the forum.